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o 1944- A. F. POTT CONTROLLING MECHANISM FOR ACCOUNTING MACHINES File d Oct. 25. 1959 15 Sheets-Sheet l A. F. POTT Oct. 31, 1944.

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Oct. 25, 1939 15 Sheets-Sheet 2 A. F. POTT CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Oct. 25, 1939 15 Sheets-Sheet 3 Z77V6/??a5 6 W 0 Q, 400, I w a 9 6 a, 5 4 w Q 54 5 44 M M4 w 0 4 4 m 0 4 .4# M j 7 Q 0 4 a 4 0 04 6 WM 5 5 l a F w M 7. 6

' Oct. 31, 1944. POTT v 7 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHInES Filed Oct. 25, 1939 15 Sh eet-Sheet 4 Oct. 31, 1944. PQTT 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Opt. 25, 19:59 15 Sheets-Sheet 5 A. F. POTT 7 2,361,707

. CONTROLLING MECHANISM F OR ACCOUNTING MACHINES Oct. 31, 1944.

Filed Oct. 25, 1939 15 Sheets-Sheet 6 0a. 31, 1944. A P T-r 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Oct. 25, 1939 15 Sheets-Sheet 7 47a 265 .7 ml 434 5 Z 4Z9\\4\7 496 4956 39 4 3 M 444 A. F. POTT Oct. 31, 1944.

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed 001;. 25 1939 15 Sheets-Sheet 8 A. F. POTT oci. 31, 1944.

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed 001:. 25, 1939 15 Sheets-Sheet 9 Oct. 31-, 1944. A. F. POTT 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Fild Oct. 25, 1939 '15 Sheets-Sheet 10 1'57 Vevr 7+ 3% 426 k 44/ my 204 fit? Oct. 31,- 1944. A F, POT-T 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Oct. 25, 1939 15 Sheets-Sheet l1 A. F. POTT Oct. 31, 1944.

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES l5 Sheet-Sheet .12

Filed Oct. 25, 1939 A. F. POTT Oct. 31, 1944.

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed t 25 939 1.5 Sheets-Sheet 0a. 31, 1944. A, F, OT 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Oct. 25, 1939 15'Sheets-Sheet l4 l v v a 0a. 31, 1944. A, F, 'POTT 2,361,707

CONTROLLING MECHANISM FOR ACCOUNTING MACHINES Filed Oct. 25, 1939 15 Sheets-Sheet l5 Patented Oct. 31, 1944 ONTROILlNG MECHANISH FOR ACCOUNT- ING MACHINES 1mm Friedrich rm, Zella-Mehlis, Germany; vested in the Alien Property Custodian Application October 25, 1939, Serial No. 301,289 In Germany November i, 1938 3 Claims.

The invention relates to a controlling mechanism for accounting machines which is especially suitable for, but not limited to, adding machines equipped with a printing mechanism for bookkeeping accounts.

Controlling mechanisms for such machines have already become known but are all more or less complicated.

This drawback is eliminated according to the invention by arranging the controlling mecha operation is performed in such manner that the controlling mechanism locks the'keys and releases the drive of the machine for another cycle for introducing the fugitive 1 and for preparing the control for total or subtotal taking, with corresponding printing of symbols, for a negative value in positive form, or for a positive tive position.

Fig. 3 is a detail view showing the parts of the control mechanism illustrated in Fig. 2 in the positions they occupy after the introduction,

of the fugitive 1.

Fig. 4 is anelevation, viewed from the right and showin the means for locking the operation keys of the machine in their initial positions.

Fig. 5 shows the positions the parts occupy upon depression of an operation key. 7

Fig. 6 shows the positions the parts occupy when the driving shaft of the machine has returned to its initial position after a partial rotation through 90 degrees.

Fig. 7 is a perspective illustration viewed from the left and the front of the machine and showing the means for locking the number and operation keys of the machine, some parts being shown at a distance fromeach other for the sake of clearness.

Fig.8 is an elevation, viewed from the right, of the'mechanism for introducing the fugitive 1, in its initial position.

Fig. 9 is a perspective illustration, viewed from in the positions. of its gears in which the nuthe right and the front of the machine, of the parts shown in Fig. 8, some parts being shown at a distance from each other for the sake of clearness.

. Figs. 10 and 11 are elevations similar to Fig. 8 and show, respectively, the positions the parts occupy when the driving shaft of the machine has returned to its initial position aftera partial rotation through 90 degrees, and at the close of the introduction of the fugitive 1.

' Fig. 12 is an elevation, drawn to a larger scale and viewed from the right, showing the totalizer and the mechanism operatively connected thereto, in their initial position.

Fig. 13 is a perspective detail illustration of certain parts as illustrated in Fig. 12, viewed from the right and the front of the machine, some parts being shown at a'distance from each other'for the sake of clearness.

Fig. 14 is an elevation which is similar to Fig. 12 showing the parts in the positions they occupy upon completion of the tens transfer in the highest order of the totalizer when its capacity occupy after the fugitive 1 has been introduced negatively. I

Idg. 1'! is a perspective illustration, viewed from the right and the front of the machine and showing a shutter for closing an inspection opening in the top plate of the machine.

Figs. 18, 19, and are other elevationswhich are similar to Fig. 12 showing, respectively, the

positions of the parts when the driving shaftwhich has performed a second partial rotation through 90 degrees upon exceeding the capacity of the totalizer negativelyhas returned into its initial position, when the tens transfer has been completed in the highest order of the totalizer if a minus value is exceeded by a plus value, and after the positive introduction of the fu itive 1'.

Fig. 21 is an elevation of the totalizer, viewed from the left.- I

Fig. 22 is a perspective illustration of the canceilin device in the totalizer, for total and subtotal taking; some parts being shown at a distance from each other, and some being broken away for the sake of clearness.

Figs. 23 and 24 are central sections through the totalizer, viewed from the left and, respectively,

meral wheels of the totalizer display 0, and in which they display 9.

Fig. 25 is a perspective illustration of the mechanism for printing symbols, viewed from the right and the front of the machine.

Fig. 26 is a perspective illustration which is similar to the one in Fig. 17 but shows a modifled shutter, and

Figs. 27 to 29, inclusive, show three distinct positions of another modified shutter.

Fig. 30 is a rear elevation of the tens-shift actuating mechanism, and

Fig. 30a is a detailed left side elevation showing the connection of the tens-shift actuating mechanism with the main drive shaft.

1. General description of the controlling mechanism The machine is preferably driven by a motor but it may also be-driven by a crank for manual operation. Through suitable gearing, the motor first turns the driving shaft In of the machine through 90 degrees in the direction of the arrow II, and then back into its initial position for the same angle against the arrow I I. These two partial rotations of the driving shaft through 90 degrees make up what will be referred to as the cycle of the machine. If a crank is provided instead of a motor, the driving shaft I is returned into its initial position by a spring.

The machine to which the controlling mechanism has been adapted, is a usual adding machine with a setbf ten number keys I2 and a set of six operation keys I3 two of which, viz. the total taking key, with its key bar 2", and the subtotaltaking key. with its key bar I91, have been illustrated in Fig. 25.

When an operation key I3 has been depressed, the motor is cut in by means of a switching member 80A (Fig. 2). At the same time, the depressed key is locked down by means that will be fully described below, until a cycle has been completed and the driving shaft III has returned into its initial position whereupon the key is released and the motor is cut out by the switching member 89A.

The motor, its switching means and its gearme, have not been illustrated.

The ten-key adding machine is equipped with a setting wheel carriage having spring-controlled setting wheels 3H) to be operated from the numat its rear which is reciprocated for a'purpose to be described below. The sectors I have teeth at both ends and a plain central portion where a movable rack 3 is arranged. This rack I, as best seen in Fig. 9, has a slot II in its-rear end to guide this end on a headed rivet 29 in the corresponding sector I. Near its front end the rack 3 is equipped with another headed rivet 29' which slides in a slot 2 I in the sector.

The setting wheels lIO which have been rotated in conformity with the values of their number keys I2, are returned into their initial positions by the drive of the machine and, in thus returning, shift the-sectors I on their rods II and I! in the direction of the arrow! in conduced. This movement is transmitted to a totalizer 4 through the racks I. The totalizer 4 has an end plate 229 at the left, an intermediate plate 294, Fig. 22, and an end plate In at the right. The end plates II! and 229 are connected by stays I ,II and IIIa which extend through holes in the intermediate plate 234. The end plate 229 at the left is mounted to swing about a trunnion Illa in the left-hand'slde platenot shown--of the machine. Similarly, the end plate In is mounted on a trunnion I" supported by the right-hand side plate of the machine and intermediate frame plate, both not shown. Addition gear wheels 8, with tens shift cams 4I (Fig. 22), are mounted on a shaft 2 I I in the totalizer 4, and subtraction gear wheels I, with tens-shift cams 4|, are mounted an another shaft 201. The gear wheels 5 and 8 are in mesh, and an intermediate gear wheel la on a shaft 2" is inserted between each subtraction wheel and the corresponding numeral wheel 42. A portion of the top plate 1' of the machine, with an inspection hole N for exposlngthe number wheels 42, has been shown In Fig. 12.

When values are introduced additively into the totalizer 4, it is rocked about its trunnions I II and Ina in the direction of the arrow I Add to engage the addition wheels 8 with the racks I on the sectors I. When values are introduced subtractively, the totalizer4 is rocked in the opposite direction, arrow Sub'l, and the subtraction wheels I of the totalizer mesh with the rack I.

The values which have been introduced are printed by types 9 on the upper ends of the sectors I which are driven against a sheet on the paper cylinder or platen III of the machine by the usual hammer mechanism 3| I. The symbols on the operation keys I! are printed by an arouate member 219, Fig. 25, as will be described in due course.

The object of the invention is as follows:

Suppose that there is a plus value in the totalizer 4 which, for instance, has 11 places. Suppose that this plus value is "000 000 005 '75 and that the minus value "752 Is to be subtracted therefrom. When the first cycle has been completed, there appears in the totalizer 4 an intermediate value which is the complement of the negative balance without deduction of the fugiformity with the values which have been intro- 15 tive 1, and, in the present instance, is 999 999 998 23. In order thatthis complementary may be printed in positive form on the paper of the platen M2, the keys are locked during the first cycleand the drive of the machine is engaged for another cycle, to introduce the fugitive 1.

The introduction of the fugitive 1 is necessary because the machine has two total taking mechanisms which are operated by a single key, the numeral wheels 42 of the totalizer 4 being returned to 0" if it is desired'to print a positive value by total taking, and advanced to 9'if it is desired to print a negative value in positive form by total taking.

During the second cycle of the machine, the fugitive 1 is subtracted from the complementary value "999 999 998 23, and the numeral wheels 42 of the totalizer 4 now indicate 999 999 998 22. The negative balance is now printed in positive form by total orsubtotal taking, the numeral wheels 42 being advanced to 9. In the present instance, the positive form of the negative balance is "1'77." When the capacity of the totalizer 4 is exceeded, in the negative sense, the inspection sp m"? N is closed by a shutter, as will be deac If, on the other hand, to a minus value, for instance, 999 999 999 951 is added a plus value "15, the complementary value "000 000 000 026 appears in the totalizer 4 after the first cycle has been completed, this beingthe positive balance without the fugitive 1. As the value 999 999 999 951 represents an understepping of the zero posiand the totalizer 4 now displays the real positive balance "000 000 000 27.

The circuit of the-motor has been closed. during the introduction'of positive or negative values by the key locking means, and to prevent interruption thereof during the second cycle, and to prevent the depression of number and operation keys during this cycle, means have been provided which will now be described.

2. The ,means for locking the number and opera tion keys As mentioned, there are as many sectors'l as there are denominational wheels-in the totalizer 4, that is, eleven. It has been described that the sectors I, by their slots Ii, are mounted to slide on the rod l secured in the left and righthand side plates of the machine, and, by their slots l0, are mounted to slide on the other rod II which is positively reciprocated in the slots ll of the sectors by the drive of the machine. As also described, the rack 3 at the left-hand side of each sector adjacent its plain central por-- tion is guided by the slot-and-rivet means 20, 2| and 20', 2|.

A pawl 23, as best seen in Figs. 1 and 9, is fulcrumed at the left-hand side of each sector about a rivet pin 22. The free end of the pawl 23 is forked. Its arm 24 lies in a notch 25 in the lower edge of the rack 3 and normally contacts the front edge 26 of the slot, so that the rack 3 can move in the direction of the arrow 2 only while positively engaged by the pawl 23. A rivet 20 is inserted in the other arm 21 of the pawl 23 and extends through an ovate or-drop shaped hole 29 in the sector I and into a longitudinal slot 30 in the corresponding tens-shift member on the addition gears G cooperate with the cam 39 of the corresponding tens-shift members 3| when the numberwheels 42 move from "9" to "0. When the totalizer 4 is turned in the direction of the arrow "Sub 1, for subtraction, the

. cams 40 on the subtraction gears 3 perform a similar function with respect to the cams 33 when the number wheels 42 move from 0' to "9. By these means, the tens transfer to the next higher denomination is prepared for operation. For completing the tens transfer, the tall 32 of each tens-shift member 3|, with the exception of units shift member 3|, has a rearward extension 43 for cooperation with the tens-shift actuatin mechanism indicated generally at 403, Fig. 1.

The tens-shift actuating mechanism is well known in commerce and is embodied in a tenkey adding machine marketed under the trade name Mercedes, and comprises a plate I 3| and the tens-shift member 3| of the units places The tens-shift members 3|, as best seen in Fig. 7, have' each a slotted tall 32 by which they are guided on a rod 34, and an arcuate slot 33 in the body which engages about an abutment rod 35. A spring 36 whose rear end is connected to a hook projecting from the member 3|, and

whose front end is securedto a transversely extending rod 36', pulls the member in upward direction until the lower end 31 of its arcuate slot 33 bears against the rod 35 from below, thus defining the initial position of the member 3|. With the exception of the tens-shift member 3| at the right-hand side of the sector at the units the totalizer 4 is rockedabout its trunnions I53 and |53a in the direction of the arrow "5 Add" in Big. .1, for-addition, the tens-shift cams 4| secured to the machine frame at the rear, extending transversely of the machine and having a plurality of vertically arranged parallel slots 402 which receive and guide the ends of the 61'. tensions 43 of tens-shift members 3|. When the members 3| are :in their normal or rest positions (Fig. 1), the rear ends of the extensions 43 are flush with the rear surface of the plate 4".

When. a tens-shift member 3| is actuated by its corresponding'cam 30 or 40, its extension 43 is moved to the left to the position shown in Big. as, into the path of movement of a toothed cam wheel 403. Curved latches I are journaled in annular grooves 442 in rod 34 and interposed between the extensions 43. Thelatches are tensioned counterclockwise by springs 443 between the lower ends of the latches and the rod 00. When the machine is at rest, a universal bail 444 secured on the driving shaft I0 abuts upward extensions 445' formed on the latches 4 to restrain the offset ears 440 formed on the latches 441 from engaging shoulders 441 formed on the tens-shift members 3|, as shown in Fig. 1. When, however, the machine starts a cycle of operations and the universal bail 444 swings clockwise away from the latches 44|, thelatches are permitted to rotate counterclockwise under the tension of their springs 443 to bring the ears 440 into tensioned engagement with the surfaces 440 lying immediately beneath the shoulders 441 of the latches. When a tens-shift member 3| is moved from its normal or rest position, under the action of its corresponding cam 38 or 43, its extension shifts to the left to the position shown in Fig. 2a, and the ear 446 of the corresponding latch 44| engages the shoulder 441 to hold the tens-shift member latched in the position shown in Fig. 2a in readiness to be actuated by the toothed cam wheel 403, as will hereafter be described.

Wheel 403 is mounted on one end of a stub shaft 404 jcurnaled in a bar 405 suitably mounted for horizontal reciprocatory sliding movement in recesses such as 4,0l a (Fig. 30) in the rearwardly projecting flanges 40") formed on the plate 4". A pinion 406 secured on the opposite end of the stub shaft 404 meshes ,with a rack 401 secured by screws 408 to the machine frame. An upstanding projection 440 on the rack 401 and the teeth on the rack serve to hold the bar'405 for.

sliding movement within the recesses "In. A

,link 409, pivoted at 4|0'to an upstanding projecdisposed link 4|5, the lower end of which has a lug and slot connection with an oscillating member 449 (Fig. 30a) loosely mounted on the drive shaft l0. An arm 450 secured to the shaft has an inturned flange 45| riding within a segment-shaped opening 452 formed in the oscillatory member 449. During the clockwise movement of the drive shaft l0 at each machine cycle, the inturned flange 45l, after a substantial idle movement within the segmental opening 452, engages the upper wall of the opening and rocks the oscillatory member clockwise to impart upward movement to the link 4| 5. During the succeeding counterclockwise movement of drive shaft |0 at each machine cycle, the inturned flange 45| retraces its path and a substantial idle movement in the segmental opening 452, engages the lower wall of the opening to impart downward movement to the link 4|5. By the above connections the link H is reciprocated vertically during each cycle of the machine and, in turn, rocks the bell crank 4|3 first counterclockwise, and then clockwise, about pivot 2 during each machine cycle.

Through the connection of link 409, this movement shifts the reciprocatory bar 405 first to the right, as viewed in Fig. 30, and then to the left, during each cycle of the machine, causing the pinion 406 to be rotated by engagement with its rack 401 and, in turn, causing rotation of the toothed cam wheel 403. The timing of the rightward movement of the reciprocatory bar 405 and clockwise rotation of wheel 403 is such that the teeth of wheel 403 engage seriatim the rear ends of any extensions 43 that may have been latched in the path of movement of the wheel by the action of cams 38 and 40 and the latches 44|, shortlyafter such latching action occurs.

Following the engagement of a tooth of wheel 403 with an extension 43, the continued rotation of the wheel causes the tooth to cam the extension, together with its tens-shift member 3|, downwardly to the position shown in Fig. 2, thus effecting a tens transfer as will hereinafter appear. The lower downwardly ofiset edge 4|5 of the left end of the reciprocatory bar 405 engages the upper edge of the extensions 43 as they are depressed, to retain the extensions depressed and this holds the shoulders 441 away from the ears 446, as shown in Fig. 2, until that point in the cycle when the totalizer 4 is disengaged from the sectors I, thus insuring the registration of the transfer upon the totalizer before the reciprocatory bar 405 is returned leftward to its normal or home position,'as shown in Fig. 30. As the reciprocatory bar 405 moves to the left its downwardly ofiset left hand end successively releases the extensions 43 from the position shown in Fig. 2, whereupon such extensions of the tensshift members return to the positions shown in Fig. 2a under the tension of the springs 36. Also the latch-controlling bail 444 swings counterclockwise and engages the extensions 445 of the latches 44| withdrawing the ears 445 from latching position relatively to the shoulders 441 of the tens-shift members, whereupon the extensions 43 are released and the tens-shift members 3| restore to their normal positions shown in Fig. 1 under the tension of springs 35.

Arranged at the left of the sector l which corresponds to the highest denomination is an extra tens-shift member 3|, Figs. 1 and 7. The cams 34 and 39 of this extra. member cooperate with the tens-shift cams 4| and-40 for the gear wheels 5 and 0 of the highest denomination. A pin 44 is riveted into the extra member 3| and cooper ates with the upper end 45 of the left-hand arm of a coupling frame 41, whose right-hand arm I25, Fig. 7, has an extension |24, the free end I23 of which engages a pin I22 in the tens-shift member 3| of the units denomination. The arms and I25 are fulcrumed on a rod 40 secured in the left-hand side plate and in an intermediate frame plate-both not shown-of the machine.

A bolt 49 is screwed into the lower end of the left-hand arm 45 of the coupling frame 41 and on this bolt is pivoted the rear end of a locking slide 50 whose front end carries a laterally ex tending lip 63 and is slotted at 52 for sliding on a headed screw 5| in the left-hand side plate of the machine. A spring 53 whose front end is connected to'a lug 54 extending from the lower edge of the locking slide 50, and whose rear end is anchored on a rod 55, pulls the slide 50 to the rear against the arrow 55 and turns the coupling frame 41 against the arrow a. The initial position of the slide 50 and frame 41 is defined by the end 45 of the arm 45 engaging the pin 44 on the extra tens-shift member 3|.

A frame for locking the operation keys II, as best seen in Figs. 1 to 7, comprises a cross bar 00, an arm 19a at the left, and an arm 18 at the right by which the frame is pivoted about a rod 5| secured in the side plates of the machine. The arm 19a is held on the rod 6| by a spring washer S2. Secured to the inner side of the arm 13a is a pusher 59 which extends to the rear and is equipped with a horizontal lug 50 extending to the right from its upper edge, and a hook 10 at its rear end. A lug 51 extends to the left from the upper edge of the locking slide 50 for cooperation with the lug 50 of the pusher 59. A catch 53 is mounted to swing on the rod 6| at the inner side of the arm 19a. The catch 53 has a lug 55 which extends to the left and is held against the upper edge of the pusher 5! by a spring 44 whose lower end is anchored in the pusher 53 and whose upper end is connected to 8. lug 55 at the upper end of the catch 53. This defines the initial position of the catch 53. Notches 51 and 68 are formed in the lower edge of the catch 53 for engaging alternately the lip 00 of the slide 50 which extends to the right from the slide.

The means for locking the number keys I: will now be described. The hook 10 (Figs. 1, 2, 3 and '1) which extends to the right from the rear end of the pusher 59, cooperates with an arm 1| forming part of a locking-control frame 12 fulcrumed about a shaft 13 in the left-hand side plate of the machine and an intermdiate frame platenot shown. An arm 15 extends in forward direction from the frame 12 and a. spring 14 turns the locking control frame 12 anti-clockwise and the front end of the arm 15, Fig. 1, engages a locking strip 11 iulcrumed about a shaft 16. The locking strip 11 is turned clockwise and engages lugs 18 on the key bars of the number keys l2. When a key I! is depressed, its lug 14 swings the locking strip 11 anti-clockwise which, through arm 15, turns the locking control frame 12 clockwise against its spring 14, and the arm 1| of the frame 12 engages below the hook 14 at the rear end of the pusher 5!.

Secured to the inner side of the right-hand arm 19 of the operation key locking frame 50, Figs. 4. 5, 6 and '7 is a bracket 34 which at its rear end carries a spring hook 0|. from this to a spring hook 33 of an unlocking armuwhosehubisbenttotheshapeofthe A spring 32 extends asomov letter U and is placed on the right-hand aid of the bar 8| at the outer side'of the arm I8. The spring 82 pulls a lug 88 of .the unloekins arm 88 against anabutment 88 on the bracket 88, as best seen in Fig. 5. A rivet pin 81 is inserted in the arm 88 and on this is pivotally mounted and held by a spring washer 88, the front end of an unlocking slide 88 whose end is slotted at 88 and is mounted to slide on a headed rivet 8| in the right-hand side plate of the machine. A lever 88 is pivotally connected to the unlocking slide 88 by a rivet pin 82, and a rivet 85 which engages in a recess 88 in the lever 98 limits the swinging movement of the lever 88 with respect to the slide 88. A spring 81 which connects a pin 88 in the lever 88 to therivet 8| by which the slotted rear end of the unlocking slide 88 is guided, turns the lever 88 anti-clockwise and holds the base of the recess 88 in the lever 88 against the rivet 88 in the unlocking slide 88. This position is shown in Fig. 4. The rear end 88 of the lever 88is engaged by 9. lug I88 (Figs. 4 to 6) on a cam plate llI'mountedto rotate on the driving shaft I8 by a square hearing hub I82. The lug I88 extends to the right from the cam plat "I and its front side 88 engages the'end 88 of the lever 88. The cam plate I8i performs the same cycle as the machine,

II, and the same angle in the opposite direction,

' as described for the driving shaft I8. The means for actuating the cam plate I" from the drive of the machine have not been illustrated.

The front end I88 as best seen in Figs. 4, 5, 8 and 7 of the lever- 88 isrecessed at I88 for engaging a lug I88 extending to the right from the lower end of a connecting rod I88. The upper end'of the connecting rod I88 is pivoted on a rivet pin I88u, Fig. "I, at the rear end of an operating frame I81 fulcrumed about a shaft-I88 secured in the right-hand side plate and an intermediate frame plate, and held by spring wash ers (not shown). A spring I88, Figs. 4. 5, and 8, whose upper end is connected to a spring hook II8 of the connecting rod I88, and whose lower end is anchored in a holder III below the bottom plate H2 of the machine, tends to turn the connecting rod I88 anti-clockwise as viewed in Figs.

4 to 8. The connecting rod I88 extends through ahole III8inthebottomplate ll2andthespring" I88 holds the rear edge 8 of the connecting rod I88 against the rearend 8 of the 116191". M l

the same time, the spring I88 turns the frame I81 clockwise. A tongue II8 extends to'the left from the front end of the frame I8I for tion with the operation keys I8, as will presently V slide I88, at IIIa. Springs Illb tend toturnthe' 3. The operation of the locking means for the keys 12 and 13 The operation of the locking means when the capacity of the totalizer is exceeded in the negative direction will now be described. Assume by way of example that it is intended to introduce the numeral "2 subtractively into the totalizer 8 which is in zero position.

When the number key I2 with the numeral 2" is depressed, the corresponding setting wheel 8 (Fig. 1) which, as described, is mounted on a setting-wheel carriage and controlled by a, spring, is rotated for two units by mechanism, not shown. At the same time, an abutment I8 on the said key I2 acts on the locking strip 11 and swings this anti-clockwise about its shaft I8. The strip 11 acts on the arm I5 of the locking-control frame I2 and swings this frame clockwise about the shaft 18 against the action. of the spring II.

when the number key I2 is released the setting wheel carriage is moved to the left one step and the setting wheel 8I8 which, as mentioned, has been rotated for two units, is moved into operative connection with the sector I of the lowest calculating order. For calculating the value "2" subtractively, the subtraction key I8 is depressed audits bellerank III is turned anti-clockwise.

The bellcrank III now exerts pressure on the moving its rear end 88 away from the lug I88 of the cam plate I8I. The'unlocking-slide 88 and the lever 88 are now shifted underthe action of the spring 81 to the rear, as indicated by the arrow III, until the end 880 of the slot 88 in the unlocking slide 88 bears against the headed rivet 8I. The front end of the unlocking slide 88 is pivotally connected to the arm 88 at 81, Figs. 4,

5 and 6, as.described, and when the unlocking slide 88 is shifted in the direction of the arrow I2I, the arm 88 is turned about the bar GI anticlockwise, as viewed in Fig. '7. Now the lug 85 of the arm 88 is in engagement with the abutment 88 of the bracket 88 which, as described, is secured to the right-hand arm I8 of theIocking bar 88. The bracket 88, the arm 88, and the locking bar 88 are now turned anti-clockwise bellcranks III clockwise. At its upper end, each bellcrank III has a sector-shaped com, with a notch H8 and a tooth I28 at thelower side 'of the notch II8. Under the action of the spring I88 the tongue II8 of the operating frame I" bears upwardly against the lower edges olthe about the bar 8I. This causes the locking bar 88 to enter the notch m, Fig. 4, of the bellcrank )III allotted to the subtraction key I8, holding the subtraction key depressed. At the same time,

the locking bar 88 engages below the teeth I28 of the bellcranks II'I allotted to the other operation keys. preventing depression of another oporation key.

when the locking. bar 88 is moved anti clockwise into its locking position, as shown in Fig. 2, the hook I8 at the rear end of the pusher-88- whieh, it will be remembered, is secured to the left-hand arm 18a of the locking bar 88--moves toward the front edge of the arm II on the locking control frame I2 and, through the means bellcranks I. When one. of the operating keys 8 operatively connected to this-frame 12, as de- 

